Motor Fault Analysis
一、How to identify motor coil fault ：
When the motor coil burns out, it means that the insulation of the motor coil is damaged, this will cause short-circuit tripping after the coil is energized.
二、Motor coil insulation damage include:
- Short circuit between coil turns
- Motor phase burnout
- Motor overload burned out
- The motor is damp and the insulation value is destroye
三、Difference of insulation damage and fault analysis
- coil Short circuit
（1）most of the coil is good, partial burn out ,as the picture shows
①the insulation layer of wire is damaged and When the motor is used, the coil voltage exceeds the breakdown voltage, then the insulation value is completely destroyed at this time.
—– How to Judge, as long as the motor can run normally sometimes,You can eliminate this point of failure,it always happened at new motor , and the running motors rarely appear.
②During motor operation , have solid object enters or rotor parts fall off, causing coil broken. The insulation of the coil is damaged then have short circuit fault.
—— How to Judge, the motor has been running for a long time, the current and voltage are very stable, but fault occurs immediately. Generally, the motor will appear after being put into operation for a long time.
③ The motor has been running many times normally, but it cannot be started suddenly with a trip fault occurs.
—- How to Judge: the new motor has been started without problems, after multiple starts or frequent starts, the failure occurs. It usually appears when new motor ,This is caused by frequent start-up and the motor is in an over-current state, which is caused by various factors;
2、coil burns out due to phase loss
（1）the motor coil shows regular local burnout；as the picture shows